Sanding machine



Oct. 10, 1933. A ELMENDORF 1,929,946

SANDING MACHINEY Oct. l0, 1933. A. ELMENDORF SANDING MACHINE 3 Sheets-Sheet 2 Filed 000. 2. 1930 oct. 10, 1933. A ELMENDORF 1,929,946

SANDING MACHINE Filed Oct. 2, '1930 3 Sheets-Sheet 3 Patented Oct. 10, 1933 messie t Y i SANDING MACHINE Armin Ehnenaorffchcag, nl., mism: to 'The Flexwood Company,

ware

a corporation of VDela- Application October .2, 193i), Serial No. .485,965 t 2 chine.

The present invention relates to machines .for sanding or polishing the face of a piece of work, particularly thin veneer mounted lon a flexible backing, and has for its object to produce a simple and novel machine of this .kind which will make it possible effectively to treat every part of the surface of the work without requiring too much material tobe removed and without danger of injury to the Work when the face that is being operated upon is thin veneer.

The simplest way of sanding a sheet is kto feed it past a rapidly revolving sanding roll. However; when the work is a thin flexible sheet, itis not a simple matter to bring every part -of the surface into contact with the sanding roll under just the right pressure. I have found that the desired results may be obtained by utilizinga revolving cylindrical brush turning at ythe 'same peripheral speed as the sanding roll but in the opposite direction, to press the sheet against the Asanding roll while the sheet .is being fed be` tween the roll vand the brush .in the direction that the roll tends to move the sheet while in contact with the same. In order to `protect the vbrush against rapid useless Wear when there is no` its objects and advantages, reference may behold to the following detailed description taken in connection with the laccompanying drawings,

wherein: Y

Figure 1 is a side elevation of a machine constructed in accordance with the present invention; Fig. 2 is a sectional view of the slip ioint in the driving shaft for the feed rolls to permit reversal of the direction of the feed, fragments of the bearings for the shaft being also shown; Fig. 3 is a section on line 3-3 of Fig. 2; Fig. 4 ls a central vertical longitudinal section through the machine, the base being broken away, and the sanding and pressure rolls being shownseparated from each other; Fig. Sis a View on a somewhat larger scale `than Fig. 4, on the same -plane as the latter, showing only a fragment of the machine, the rolls being closed on the work; Fig. 6 is an end View of the machine, being a view of that end which is at the right hand side of Figs. 1 and 4; and Fig. 7 is a side View of a (c1. sinn;A Y l fragment ofthe machine' showing the gear loetween the two feed rolls. l

Referring to the drawings, 1 represents a suitakhle frame having at the topV a horizontal table 2 onwhich a sheet to be treated .is-l laid and along which it is fed. This table terminates at about v the middle of the machine, below a horizontal transverse sanding roll. kBelowfand parallel with the sanding roll is a-pressure roll 4 having radial peripheral-bristles and therefore taking theform of a large cylindrical brush. At least one of the rolls is mounted so as-to be bodily movablefrom and toward the other so` that the rolls may be opened and closed on the work. In the arrangement shown, the roll 4 is the one that is bodily movable. this end, the ends ofV the shaft 6 upon which this roll is ,fixed are jonrnalled in the outer ends of approximately horizontal .arms 7 of two AL-shaped brackets, one on each side ofthe machine these brackets being hung on the frame through a shaft 8 that passes through the frame land through the brackets at the juncture of each of the horizontal arms with the corresponding vertical arm 9 of the bracket. Toward the front end of the machine is a vertical hand lever 10 connected bya link 11 to the lower emi of the Yvertical .arm of V'one of the brackets. By vmoving the levenjthe brackets will be swung so as to raise and lower the pressure roll, depending Vupon' the direction in which the lever is shifted. On the frame beside the hand llever is atoothod segment 12 adapted to be engaged by a catch 13 on 'the lever for the purpose of lockingthe lever in anyV position to which it may be brought. j

A sheet tobe sanded islaid on the table 2 and along the same V'until its advance end reaches a point that will. permit Vit to be .engaged by bothrolls when-they'are closedupon the same. Then, the rolls being driven at a `high peripheral speed in opposite directions, but in suchvdirections that they will tend to act as feed rolls to draw the-sheet ahead, if the lower or "pressure roll is raised so that the bristles thereon will press the sheet against the under side of the sanding roll, every minute part of the surface of the sheet will be' brought into intimate contact with the sanding roll without exerting greater pressure at one pointthan another. The sheet being fed slowly while the rolls are revolving rapidly, there will be a progressive even treatment of the face of the sheet from the end inwardly. In Fig. 5 I have shown a sheet in the act of passing through the rolls, the sheet being indicated at A. The feeding of the sheet is from left to right and the rolls rojoint.

tate in the direction of the arrows. It will be seen that the bristles are bent or deflected back# ward where they are in engagement with the work. thereby exerting a light but constant pressure on the sheet.

In the particular arrangement shown there is fixed to the shaft 8 a bracket `15 on the upper end of which is carried a table section 16. 4When the pressure roll is swung down, the table section 16 also moves down, as shown in Fig. 4. However,

when the pressure roller is swung up, the table r.

section 16 aligns with the table 2, as shown in Fig. 5. l

The work may conveniently be fed past the rolls by means of a pair of feed `rollers k17- and;18,v one lying above the table 2 and the other below the table at some distance from` the rolls. .Between the feed rollers and the rolls there may 'be placed a rotary brush 19 adapted to engage wththeI face of a sheet passing through the machine and being rapidly revolved in the same'direction as is the roll 3 thereby serving to hold'the sheet down on the table and to sweep toward the rear of the machine any sand or dustthat may be deposited on the sheet before it reaches the sanding roll.

. The various rotatable elements may be driven in any suitable way. In the arrangement shown, there is an electric motor 21 mounted on the top ofthe frame in rearfof the sandin'groll. A belt 22 running over a pulley 23on the shaft 24 of the sandingl roll causesthat `roll to revolve in the proper direction when the motor is running. The shaft 24 and the shaft 25of the rotarybrush 19 have thereon pulleys 26 and 27 respectively, over whicnpulleys passes a belt 28 that causes the brush to revolve whenever the sanding roll is rotating. A second belt 29, driven directly by the motor, runs over'one step of a 3-step pulley 30 rotatably supported on the frame of the machine. A belt 31 runs Vover a second step on the pulley 30 and a'pulley 32 on the shaft 6 of the pressure roll; the belt 31 being crossed so that the pressure roll will be driven in the opposite direction from the sanding roll'. A belt 33,` running over the third step of the pulley '30, drives a pulley 34 on the end of a horizontal shaft 35 extending across the rear end of the machine. On the opposite end of the shaft 35 is a worm 36 meshing with a wormwheel 3'7 on a shaft 38 that extends along the side of the machine toward the front end. 1 The shaft 38,terminates at about the middle of the machine and there, as best shownin Figs.` 2 andl3, is provided with, an elongated square axial opening 39. Into this Y opening extends a square stem 40 on the rear end of a shaft 41 that lies infront ofthe shaft 38 and is aligned vtherewith so as to form a continuation thereof. It will thus be seen that the shafts 38 and 41 are connected by a slip joint that will permit the shaft 41 to be moved in the direction of its length while the shaft 3 8 is held against endwise movement. If desired, a sleeve 42 may be placed around the meeting ends of the shafts 38 and 41 so as effectively kto cover the On the shaft 41, and spaced apart from each other, are two bevel pinions-43 and 44. These pinions co-operate with aV bevel gear 45 fixed to the Shaft 47 of the lower feed roller 18. The parts are so proportionedthat when either pinion is in mesh withvthe gearwheel the other,

stands clear of the gear wheel. The slip joint between the shafts 38 and 41 permits the shaft 41 to be shifted, through a handle 46 or otherwise, so as to bring either pinion into mesh with the gear wheel. It will be seen that the pinions serve to drive the lower feed rolls in opposite directions so that when one of the pinions is in mesh with'the gear wheel the work isbeing fed into the machine and, when the other pinion is in mesh, the work is fed or drawn backwards out ofjthe machine. The feed rollers are of course gearedtogether so that they will rotate in opposite directions at the same speed whenever the lower roller is driven. f This is accomplished by placing on the feed roller shafts 4'7 and 48 similar gear wheels 49 and 50 that mesh with each other.

The particular machine shown requires that the sheet be removed and turned end for end after it has been fed into the machine far enough to bring the trailing end into the vicinity of the feed rollers. Therefore, before the trailingV end of the sheethas passed through the feed rollers, the feed rollers are reversed, thereby withdrawing thesheet from the machine. After the sheet has been v'withdrawn from the machine it is simply turned end for end and the feed rollers are again causedvto move it toward the sanding roll.

v While I-'have illustrated and described with particularity only a single preferred form of my invention, I do notdesir'e 4to be limited to the 105 form of acylindrical brush between the tables,

a support common to said second-roll and said second table movablein a direction to permit the rolls to be separated from each other or be brought in contact/with each other, means for revolving said rolls in opposite directions at a 1'20 high peripheral speed, and means for slowly feeding the work-across the tables and between the rolls. 2,. In a machine ofthe character described, a

Work-treating roll, a table on one side of the roll approximately tangential thereto, a member below the plane of said table having a free end lying behind the aforesaid roll, means supporting the other end of said member to permit it to'swing about an axis parallel with the axis of rotation of the aforesaid `roll,'a second roll in the form of a cylindrical brush on the free end of said member, and a second table mounted on said member between said` second roll and the hinge axis thereof, thekparts being so proportioned and arrangedthat in one position of said memberthe second roll is held in contact with the first roll and said second Atable is approximately in the same plane as theother table, whereas in another position of said member, said second roll is spaced apart from the first roll, means for revolving said rolls in opposite directions at a high' peripheral speed, andY means for'slowly feedingv the work across the tables and between the rolls.

ARMINELMENDORF. 

